From what I read and from plans I heard from the company I work for, I think we will have to wait till they are ready to roll out /64 to consumer routers/gateways. The first phase will only be able to support a single address which wouldn't make sense to use with pfSense. I hope they stick to this plan because I've heard that the ISP may just provide a router/gateway that will hand-out IPv4 and IPv6 addresses to devices that are behind it. If they go this route, then we wouldn't be able to control the router; only the ISP/MSO would be able to configure it. This would only be for residential customers. Business customers would be handled differently. Time will tell, I hate that my company is usually last to deploy products but we learn from what other companies do and avoid their mistakes.

their reasoning is that the amount of directly connected users is not trivial. So this should be a fairly harmless afair.

Also, if the DHCP6 client is activated on the WAN interface pfSense will pick a DHCP6 address but there will be no prefix delegated when requested from the DHCP6 server.

In the near future you can request a prefix delegation from the DHCP6 server and that should provide you with a routed subnet for the LAN.

From my understanding from talking to Comcast they want to have generic devices from Netgear and D-link that work with DHCP-PD. They are not going the route that Ziggo in .nl is with the UBEE modems/routers/wifi gateways.